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Abstract

Background

The objective of this study was to determine the contamination rate of the healthcare
workers' (HCWs') mobile phones and hands in operating room and ICU. Microorganisms
from HCWs' hands could be transferred to the surfaces of the mobile phones during
their use.

Methods

200 HCWs were screened; samples from the hands of 200 participants and 200 mobile
phones were cultured.

Results

In total, 94.5% of phones demonstrated evidence of bacterial contamination with different
types of bacteria. The gram negative strains were isolated from mobile phones of 31.3%
and the ceftazidime resistant strains from the hands were 39.5%. S. aureus strains isolated from mobile phones of 52% and those strains isolated from hands of
37.7% were methicillin resistant. Distributions of the isolated microorganisms from
mobile phones were similar to hands isolates. Some mobile phones were contaminated
with nosocomial important pathogens.

Conclusion

These results showed that HCWs' hands and their mobile phones were contaminated with
various types of microorganisms. Mobile phones used by HCWs in daily practice may
be a source of nosocomial infections in hospitals.

Background

Nosocomial infection is an important problem in all modern hospitals. As early as
1861 Semmelweis [1] demonstrated that bacteria were transmitted to the patients by the contaminated hands
of healthcare workers. Hospital operating rooms (OR) and intensive care units (ICU)
are the workplaces that need the highest hygiene standards, also the same requirements
for the personnel working there and the equipment used by them. Some epidemiological
studies have implicated environmental surfaces in the transmission of bacteria [2-4]. Mobile phones are widely used as nonmedical portable electronic devices and it is
in close contact with the body. It is used for communication by health care workers
in every location including OR and ICU. Studies do not include direct comparisons
of transmission rates of bacteria from surfaces to hands. The risk of infection involved
in using mobile phones in the OR and ICU has not yet been determined as there no cleaning
guidelines available that meet hospital standards. However, the mobile phones are
used routinely all day long but not cleaned properly, as health care workers' (HCW)
may do not wash their hands as often as they should. The aim of the present study
was to evaluate the role of mobile phones in relation to transmission of bacteria
from the mobile phone to the healthcare workers' hands.

Methods

The study was conducted in the eight beds of the mixed tertiary intensive care unit
and 14 operating rooms. A total 200 staff – 15 senior, 79 assistant doctors, 38 nurses
and 68 healthcare staff – were screened; cultures were subsequently obtained from
the dominant hand of participants and their mobile phones at the same time. Gender,
profession and duration of their profession, ring use, dominant hands of HCWs, routine
cleaning of the mobile phones was recorded. A sterile swab moistened with sterile
saline was rotated over the surface of both sides of mobile phones; second swab was
rubbed over the entire ventral surface of the dominant hand (including ventral surfaces
of the thumb and the fingers) of HCW's. The sampling of the dominant hand and mobile
phone swabs (twice for hands and twice for mobile phones) were immediately streaked
onto two plates that consist of blood agar supplemented with 5% defibrinated sheep
blood and eosin methylene blue agar. Plates were incubated aerobically at 37°C for
48 h. Isolated microorganisms were identified using gram stain, colony counts, morphology,
catalase and oxidase reaction and all isolates were allocated to the appropriate genera.
For identification of gram negative bacteria VITEK 2 (bioMerieux, France) system was
used. A slide coagulase test differentiated staphylococcal isolates into Staphylococcus
aureus and coagulase-negative staphylococci (CoNS). Oxacillin sensitivity of the Staphylococci
and ceftazidime sensitivity of the gram negative isolates were investigated by disk
diffusion method according to Clinical Laboratory Standards (CLSI) criteria [5].

The protocol was approved by the ethical committee for human experimentation of Ondokuz
Mayis University Faculty of Medicine and informed consent was obtained from the participants.

Statistical analysis

Categorical variables were assessed by Chi square analysis. Non-categorical findings
were assessed by the student t test or Man-Whitney U test. P values < 0.05 were considered
significant. SPSS for Windows 13.0 software (SPSS Inc., Chicago, USA) was used for
these analyses.

Results

The rate of bacterial contamination of mobile phones is 94.5%. The isolated microorganisms
from mobile phones and hands were similar (Table 1). Some of them are known to cause nosocomial infections. Hand contamination rates
of HCWs and their personal mobile phones are shown in Table 2. It was found that 49.0% of phones grew one bacterial species, 34.0% two different
species, 11.5% three or more different species and no bacterial growth were identified
in 5.5% of phones.

Those S. aureus strains isolated from mobile phones of 52.0% and those strains isolated from hands
of 37.7% were methicillin resistant. The gram negative strains were isolated from
mobile phones of 31.3% and the ceftazidime resistant strains from the hands were 39.5%.
At the study period our nosocomial isolates at ICU were: 33.3% staphylococci, 21.4%
non-fermentative gram negatives, 21.4% coliforms, 7.1% enterococci, 11.9% yeasts.

The rate of routine cleaning of HCW's mobile phones was 10. 5%, which means 89.5%
of the participants never cleaned their mobile phones. Although the assistant doctors'
phones have higher colony count there was no significant difference in the rates of
specific types of bacterial growth and colony counts isolated on all groups' mobile
phones (Table 2).

Table 2. Hand contamination rate of HCWs and colony count with or without ring

25.5% of the entire study population had one or more rings. The mean colony count
was higher in ring using staff's phones but there was no significant difference between
rate of contamination and colony count (Table 2) (p > 0.05).

Discussion

In this study, the use of mobile phones by HCWs working in OR and ICU not only demonstrated
a high contamination rate with bacteria but also more importantly contamination with
nosocomial pathogens. The possibility transmissions of nosocomial pathogens by electronic
devices such as personal digital assistants, handheld computers, and bedside applications
were previously reported and some of them were epidemiologically important drug-resistant
pathogens [6,7]. Isaacs et al. [6] showed that the main growth was of coagulase-negative staphylococci from 25 keyboards.
Two keyboards grew S. aureus, both of which samples were susceptible to methicillin/flucloxacillin. Neely et al.
[8] also identified nosocomial A. baumannii infection on keyboards as a reservoir in burn units and ICUs. Butz et al. [9] stated that immobile phones might carry pathogens as well; stationary phones in a
daycare facility were contaminated with rotavirus Rusin et al. [10] documented that hand-to-mouth transfer of microbes after handling contaminated fomites
during casual activities. Singh et al. [11] reported that over 47% of immobile phones were contaminated with pathogenic microbes.

These results suggested that close contact objects that were contaminated could serve
as reservoirs of bacteria where could be easily transmitted from the mobile phone
to the HCWs' hands. During every phone call the mobile phones come into close contact
with strongly contaminated human body areas with hands to hands and hands to other
areas (mouth, nose, ears). Herein mobile phones are particularly problematic when
compared to immobile devices and it may facilitate transmission of bacterial isolates
from patient to patient in wards or hospitals.

Some authors [12,13] showed that HCWs' mobile phones were contaminated with nosocomial pathogens. The
result of our study demonstrated cross transmission of bacteria between HCWs' dominant
hands and one third of mobile phones. Gram negative bacteria are very important nosocomial
pathogens and HCWs' mobile phones were carried ceftazidime resistant Gram negative
isolates and half of S. aureus isolates were resistant to methicillin. However, this study was carried on a limited
scale as no molecular tests were conducted for showing clonal relation.

Our study demonstrated that the isolated microorganisms from hands and phones were
similar. It is clear that it is not possible to estimate the level of bacterial contamination
with one sampling technique. Borer at al. [12] observed that there were contaminations of hands and mobile phones only in 10% of
their staff who were sampled for once. The present study was nevertheless similarly
planned; in this study contamination rate of the mobile phones was 94.5% for one sampling.
Since no warning has been given for cleaning mobile phones to meet hospital standards,
the same rates and composition of contamination of mobile phones could be risky when
carried outside the hospital environment. Limitation or crackdown of these items would
be unpractical strategies for preventing nosocomial transmission, because mobile phones
are used by the personnel both in private communication and emergency situations in
ICU so; cross-transmissions between hands to mobile phones were assessed. Although
it seems impossible, in the light of all these findings, we should be aware of limiting
the mobile phone usage as it has high risk for spreading infections.

According to these results it is obvious that, the training of healthcare personnel
about strict infection control procedure, hand hygiene, environmental disinfection,
and eventually, optimum disinfection methods are of great importance. Otherwise, the
potential benefit of using mobile phones by the personnel for private communication
or emergency situations in ICU or OR would change into this means of communication
detrimental to hospital hygiene. Therefore, near the hand hygiene, cleaning of these
devices should be kept in mind. Prevention of contamination risk of nosocomial pathogens
and infections stands out as problem that must be weighed in mind.

Developing active preventive strategies like routine decontamination of mobile phones
with alcohol containing disinfectant materials might reduce cross-infection. Another
way of reducing bacterial contaminations on mobile phones might be the use of antimicrobial
additive materials. We could easily avoid spreading bacterial infections just by using
regular cleansing agents and rearranging our environment. In the future mobile phones
could be produced by using protective material against the bacterial contamination.

Competing interests

The authors declare that they have no competing interests.

Authors' contributions

FU carried out the design of the study, participated in the sequence alignment and
drafted the manuscript. SE participated in the design of the study and performed the
statistical analysis. AD participated in the sequence alignment and helped to draft
the manuscript. MG and KY carried out the microbiological procedures. HL conceived
of the study, and participated in its design and coordination. All authors have read
and approved the final manuscript.